Heater control wont blow on the floor but will blow air everywhere else. all the vacuum lines seem two be working

These controls are all vacuum actuated. If it isn't getting vacuum, it will not work. Check that all vacuum lines are not cracked or disconnected. Vacuum comes from the manifold to a black ball vacuum canister on the firewall under hood, from there it runs directly inside and connects to the control valves/levers. It may just have come unhooked from the vacuum distributer on the levers.

Item Part Number Description 1 18A318 Vacuum Control Motor-, Panel/Defrost Door 2 18A478 Panel/Defrost Door (Full Vacuum Position) 3 - Defrost Air Flow 4 - Side Window Demister Air Flow 5 18B545 Temperature Blend Door (Full Heat Position) 6 19860 A/C Evaporator Core 7 19A813 Air Inlet Duct Door (Full Vacuum Position) 8 - Outside Air Inlet 9 18A318 Vacuum Control Motor-, Air Inlet Duct Door 10 - Recirculated Air Inlet 11 18527 Blower Motor 12 19A566 A/C Vacuum Reservoir Tank and Bracket 13 - Vacuum from the Engine Intake Manifold 14 19B888 A/C-Heater Function Selector Switch 15 - Vacuum to the 4x4 Hub Solenoids 16 18495 Water Diverter Valve (Full Vacuum Position) 17 18476 Heater Core 18 18A559 Floor/Panel Door (Full Vacuum Position) 19 - Floor Air Flow 20 18A318 Vacuum Control Motor-, Floor/Panel Door 21 - Panel Vent Air Flow

Might be the control switch, but that is unusual. Most likely it is the vacuum hose going to the damper controlling the defoger. If it was the vacuum line to the control, then it would blow defog all of the time.

check the controller an vacuum lines

Air Flow Control
Air flow control is accomplished in the following manner:

• Primary control is through the function selector knob , mounted on the heater function selector switch, which is part of the heater control .
• The function selector knob has the following positions: OFF, PANEL, PANEL/FLOOR, FLOOR, FLOOR/DEFROST and DEFROST.
• The heater function selector switch combines a vacuum selector valve with an internal electrical switch.

• The vacuum selector valve directs source vacuum to various vacuum control motors (18A318) . Refer to the System Airflow Schematic and Vacuum Control Charts.
• An internal single-pole electrical switch is also controlled by the selector. The switch controls the electrical supply to the heater blower motor switch (18578) .
• The position of the function selector knob determines the manner in which the system will operate.
• Each position of the function selector knob is detented for positive engagement.
• You probably have a vacuum leak , Pull heater control panel an check for vacuum . A broke vacuum hose or The vacuum selector valve is bad ! Or check for a vacuum hose in the engine compartment being off somewhere !
  

air door actuator failure or vacuum leak in control lines or bad check valve in line to vacuum reservoir.

. Air won't blow out of the floor or center vents just defrost ? Do you have manual or automatic climate control ?
Air Flow Control
Air flow control is accomplished in the following manner:

• Primary control is through the function selector knob mounted on the A/C-heater function selector switch, which is part of the integrated control panel.
• The function selector knob has the following positions: OFF, MAX A/C, A/C, PANEL, PANEL/FLOOR, FLOOR, FLOOR/DEFROST and DEFROST. The A/C-heater function selector switch combines a vacuum selector valve with an internal electrical switch.
• The vacuum selector valve directs source vacuum to various vacuum control motors (18A318). Refer to the Vacuum Control Diagram , System Airflow Schematics and Vacuum Control Chart .
• Two internal, single-pole electrical switches are also controlled by the A/C-heater function selector switch. The combination of these electrical switches controls the electrical supply to the A/C clutch and heater blower motor switch (18578).
• The position of the function selector knob determines the manner in which the system will operate.
• Each position of the function selector knob is detented for positive engagement.
• Vacuum Control Motors The vacuum control motors (18A318):
  
  • are located on the A/C evaporator housing, A/C recirculation air duct and heater air plenum chamber (18471).
  • direct system airflow to the vehicle interior as determined by the remote climate control module or manual override.
  • The five-passenger seating configuration has an additional vacuum control motor mounted on the heater air plenum chamber to control airflow to the rear seat A/C register (19893).
  
  

The mode doors are operated by vacuum. Check the vacuum supply line to verify it is connected to the intake manifold. If that looks good, remove the control panel to see if vacuum is coming to the mode switch. Then check to see if the switch is transferring vacuum to the actuator lines. Here is the panel removal procedure:

1. Disconnect the negative battery cable.
2. Remove the necessary bezel(s) in order to gain access to the control head.
3. Remove the screws that fasten the control head to the instrument panel.
4. Pull the unit out to troubleshoot.

There are 2 vacuum lines that control your hvac system, one of them is either disconnected or dry-rotted and needs replaced. I was able to fix it by purchasing a 3-way splitter for a vacuum line, bought some rubber vacuum line and spliced into the cruise-control vacuum line. Worked like a charm. If it's not that, you could have a vacuum leak anywhere alone the line from the intake manifold to the evap canister

look for a broken plastic vacuum line under hood, vacuum is what controls the heater controls inside the car